Stability of the input-output properties of chronically implanted multiple contact nerve cuff stimulating electrodes

The objective of this investigation was to measure the input-output (I-O) properties of chronically implanted nerve cuff electrodes. Silicone rubber spiral nerve cuff electrodes, containing 12 individual platinum electrode contacts, were implanted on the sciatic nerve of seven adult cats for 28-34 weeks. Measurements of the torque generated at the ankle joint by electrical stimulation of the sciatic nerve were made every 1-2 weeks for the first 6 weeks post-implant and every 3-5 weeks between 6 weeks and 32 weeks post-implant. In three implants the percutaneous lead cable was irreparably damaged by the animal within 4 weeks after implant and further testing was not possible. One additional lead cable was irreparably damaged by the animal at 17 weeks post-implant. The three remaining implants functioned for 28, 31, and 32 weeks. Input-output curves of ankle joint torque as a function of stimulus current amplitude were repeatable within an experimental session, but there were changes in I-O curves between sessions. The degree of variability in I-O properties differed between implants and between different contacts within the same implant. After 8 weeks, the session to session changes in the stimulus amplitude required to generate 50% of the maximum torque (I50) were smaller (15+/-19%, mean +/- s.d.) than the changes in I50 measured between 1 week and 8 weeks post-implant (34+/-42%). Furthermore, the I-O properties were more stable across changes in limb position in the late post-implant period than in acutely implanted cuff electrodes. These results suggest that tissue encapsulation acted to stabilize chronically implanted cuff electrodes. Electrode movement relative to the nerve, de- and regeneration of nerve fibers, and the inability to precisely reproduce limb position in the measurement apparatus all may have contributed to the variability in I-O properties.     

Simplified guide for precise implant placement: a technical note

Loss of heterozygosity (LOH) at chromosome band 10q23 occurs frequently in a wide variety of human tumors. A recently identified candidate tumor suppressor gene, PTEN located on 10q23, is mutated in multiple advanced cancers. To explore whether PTEN is associated with human squamous cell carcinoma of the head and neck (SCCHN), DNAs from both normal muscle and tumor tissue in 19 SCCHN were used for detecting LOH at chromosome 10q23 and mutational analysis of PTEN by direct polymerase chain reaction (PCR)-DNA sequencing. LOH at 10q23 was identified in 6/15 SCCHN. Mutation of PTEN was identified in 3/19 SCCHN. Of these 3 patients, 2 had stage IV disease; the third patient, with recurrent, metastatic and stage III disease, showed a 36 bp germline heterozygous deletion within intron 7. Furthermore, a missense mutation at codon 501 (TCT --> TTT: Ser --> Phe) in exon 8 was also found in tumor from the same patient. Our results suggest that PTEN may play a role in the genesis of some SCCHNs.     

Dentinogenesis imperfecta: endodontic implications. Case report

OBJECTIVE: A number of dynamic tests of the hypothalamic-pituitary-adrenal axis provide evidence for a mild central adrenal insufficiency in chronic fatigue syndrome (CFS). The 1 microgram adrenocorticotropin (ACTH) test has been proposed to be more sensitive than the standard 250 micrograms ACTH test in the detection of subtle pituitary-adrenal hypofunctioning. We aimed to establish whether the 1 microgram ACTH test would support such a dysregulation in CFS, and also, given the relative novelty of this test in clinical practice and the uncertainty with regard to appropriate cut-off values for normality, to compare our healthy volunteer data with those of previous studies. PATIENTS AND DESIGN: Twenty subjects with CFS, diagnosed according to Centres for Disease Control and Prevention criteria, were compared with 20 healthy volunteer subjects. All participants underwent a 1 microgram ACTH test beginning at 1400 h. Plasma samples for cortisol estimation were drawn at 0, +30 and +40 min. RESULTS: Baseline cortisol values did not differ between CFS patients and healthy subjects. The delta cortisol (maximum increment from baseline) value was significantly lower in the CFS than the volunteer group (P < 0.05). Comparison of the +30 min cortisol values revealed no significant differences. Using an incremental cortisol of > 250 nmol/l as an arbitrary cutoff point, two (10%) of the healthy subjects and nine (45%) of the CFS subjects failed the test on this basis (chi 2 = 4.3, df = 38, P < 0.05). CONCLUSIONS: This study provides further evidence for a subtle pituitary-adrenal insufficiency in subjects with chronic fatigue syndrome compared to healthy volunteers. Disparities between our healthy volunteer data and those of other groups using the 1 microgram ACTH test suggest that the test may not be as reliable as previously indicated.     

Fentanyl decreases beta-CIT binding to the dopamine transporter

We evaluated the beginning of lactogenesis and the milk quantity until the fifth post-delivery day, before discharge, in 10 primiparae and 11 pluriparae Gypsies, as compared to 12 primiparae and 11 pluriparae Italian women. The results showed that both in primiparae and in pluriparae Gypsies, the lactogenesis started significantly earlier and the milk quantity was significantly greater than in Italian women.     

HDR and MDR intracavitary treatment for carcinoma of the uterine cervix. A prospective randomized study

The multiple goals theory of conflict management (Ohbuchi & Tedeschi, in press) postulated that participants in a conflict pursue to achieve resource goals (economic and personal resources) and social goals (relationship, identity, justice, and power-hostility). The hypotheses based on this theory were examined by the episode method, in which 207 university students were asked to rate their recent experiences of interpersonal conflicts in terms of participants' attributes, goals, and tactics. More than 80% of the subjects answered that they were motivated to achieve multiple goals in their attempts to resolve the conflicts. Social goals were found to be more strongly activated, and economic resource goals were least strongly activated. Regression analyses revealed that the effects of participants' attributes on tactical preference were mediated by goals.     

A multidisciplinary approach to restoring posterior bite collapse

Treatment planning of posterior bite collapse cases with loss of vertical dimension can be complex. In cases where a patient's vertical dimension of occlusion has been lost, there often is drifting of posterior teeth, flaring of maxillary anterior teeth, and inadequate interarch space for a restoration. These factors are further complicated by the esthetic demands of the patient and the dentist and by the use of implants to replace missing teeth. This article presents a case report of a multidisciplinary treatment plan to achieve a functional and esthetic restoration.     

Pulp remains viable following vital amputation of the mesio-buccal root of the maxillary fourth premolar in dogs

Vital amputation of the mesio-buccal root of the maxillary fourth premolar (P4) was performed bilaterally in 8 dogs. Histopathologic evaluation of the tooth structure revealed normal pulp in the remaining mesio-buccal, mesio-palatal, and distal roots and crown during a mean follow-up period of 3.5 +/- 1.9 months. Amputation site healing was characterized by a reparative dentin bridge produced by odontoid cells. Tunnel defects were observed in 13 of 16 (81%) dentin bridges. It is concluded that the pulp of a tri-rooted, periodontal disease-free tooth remains viable during a 6-month period following vital root amputation. These results point to the intriguing possibility that this may also occur in humans, however, this needs to be directly tested in man.     

Antimetabolite-induced apoptosis in Tenon''s capsule fibroblasts

PURPOSE: To analyze the computed tomographic (CT) features of intestinal Beh?et syndrome and to determine the usefulness of CT in detecting complications. MATERIALS AND METHODS: The CT scans of 28 patients with intestinal Beh?et syndrome were retrospectively reviewed. Five patients had bowel perforation, and two had peritonitis. Patterns of bowel involvement, patterns of contrast enhancement, and ancillary findings were compared in patients with complications (n = 7) and patients without complications (n = 21). RESULTS: Ten patients had polypoid lesions, nine had a thickened bowel wall, and nine had both findings. Lesion enhancement was mild in eight patients (29%) and marked in 20 (71%). Polypoid lesions were more commonly seen in patients without complications (P = .020); a thickened bowel wall was more commonly seen in patients with complications (P = .030). Seventeen of 18 patients (94%) with minimal perienteric infiltration did not have complications (P = .0003), whereas all five patients with severe perienteric infiltration did have complications. CONCLUSION: In patients with known intestinal Beh?et syndrome, CT can be useful in determining the extent of the lesions and in identifying cases in which complications are likely to occur.     

Magnetic resonance cholangiopancreatography: a novel approach to the evaluation of suspected pancreaticobiliary neoplasms

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive diagnostic method for pancreaticobiliary (PB) imaging without endoscopy, sedation, or iodinated contrast. The purpose of this study was to evaluate the ability of MRCP to depict pancreatic and biliary ductal anatomy compared to that of endoscopic retrograde cholangiopancreatography (ERCP) and to evaluate the ability of MRCP to accurately diagnose PB neoplasms. METHODS: Twenty patients had MRCP, and 17 also had ERCP. All studies were read prospectively by experienced reviewers blinded to other imaging data. Pathologic diagnosis was made in all patients. RESULTS: Bile duct dilatation seen by ERCP in 14 of 17 patients was correctly identified by MRCP in all 14 patients, and normal ducts were correctly identified by MRCP in the other 3 patients. The pancreatic duct was visible on MRCP in the pancreatic head in 17 of 20 patients, the body in 17 of 20 patients, and the tail in 15 of 20 patients. At ERCP, pancreatic duct dilatation was present in 11 cases and was identified by MRCP in 10 of them. Eighteen of 20 patients had malignant PB neoplasms. MRCP indicated PB neoplasm in 19 patients. Seventeen of these 19 patients had histologically confirmed malignant neoplasms pathologically, whereas 2 had benign pathology (both chronic pancreatitis). Among the 17 patients who also had ERCP, MRCP and ERCP correctly agreed on a final diagnosis of malignant neoplasm in 14 cases. In the three cases in which MRCP and ERCP disagreed on a final diagnosis, MRCP was correct in one and incorrect in two. CONCLUSIONS: MRCP can accurately and noninvasively delineate PB ductal anatomy and diagnose PB neoplasms comparably to ERCP. MRCP is an interesting new noninvasive method for evaluating patients with suspected PB neoplasms.     

The outcome of ankylosing spondylitis: a study of 100 patients

The outcome was studied in 100 patients with adult-onset primary ankylosing spondylitis (AS). After a mean disease duration of 16 yr, 51.5% of the patients were employed in full-time work. Cessation of work occurred at a mean disease duration of 15.6 yr, and was significantly associated with female sex, low levels of education, acute anterior uveitis, 'bamboo spine' and the co-existence of non-rheumatic diseases. Functional outcome was studied by analysing activities of daily living, and revealed similar findings in males and females. Most of the loss of function occurred during the first 10 yr of disease, and correlated significantly with the occurrence of peripheral arthritis, spinal X-ray changes of AS and development of 'bamboo spine'. After > 20 yr of disease, > 80% of the patients still complained of daily pain and stiffness, and > 60% reported daily use of drugs.